(1) Field of the Invention
The present invention relates to a cooling system for use in an engine having a movable element which requires cooling. The cooling system of the present invention has particular utility in scramjet engines where a movable cowl inlet flap requires cooling.
(2) Prior Art
As supersonic combustion ram jet (scramjet) engine technology continues to develop, an important goal will be to improve the propulsion system's operability and performance. One method of achieving this goal is to incorporate variable geometry into the engine flowpath design. Variable geometry allows for real time optimization of the engine flowpath lines for varying flight conditions. Incorporating a movable cowl inlet flap is one method of achieving variable geometry in a scramjet engine.
The operating environment of the cowl flap requires the metallic flowpath surface of the flap to be actively cooled. Since the flight trajectory of a hypersonic vehicle can include a number of different cowl flap positions, a significant heat load can be generated on the exterior surface as well. As a result, both interior and exterior surfaces of the flap require active cooling.
Designing a movable cowl flap for a scramjet engine presents many challenges. Actively cooling the flap structure represents one of these challenges.